Why? For instance, An analog signal inputted through the line-ins on Monolith 124459 and Creative X7 goes through ADC->DSP->DAC … I know this is mainly because the DSP can only be applied to a digital signal but then one cannot use units like these as stand alone amps because when the signal goes through ADC->DSP->DAC there is added distortion + noise and the signal gets degraded ?
Routing digital lines (= putting the copper on the circuit board) is easier* than routing (and shielding) analogue lines.
Plus, like you said, applying Digital processing only works on a digital signal. If done in a half-realm (digitally controlled analogue circuits) those units with all their features would cost the same as a studio recording desk.
So called “multieffects” have existed for a long while for studio and live. While technically the signal gets degraded, I don’t think a lot of people are able to tell signal paths apart by ear.
*At least for the low frequencies required for transmitting Audio via I2S or SPI
I enjoy your posts. I feel like I learn something every time I read your stuff!